I am trying to implement some cost savings, and was wondering if I could potentially replace that long horizontal frame in the center by with some sort of cable or rope. It would be good if it just hooks onto the members either directly or with some sort of plate with a hole. I was wondering what I should look up on Google or McMaster to buy something like this. The simple word "cable" or "hook" isn't really helping me narrow my search. I've tried searching things like tension hook, tension cable, etc. but still no luck.
What you need is a non-flexible "tension tie"that would not easily buckle while compressed. A stretchable cable, or a rope may not prevent the handles from rotation about the connection at the base, that would lead to large displacement. Depending on the strength required, you can consider both the solid bar or a hollow tube (preferred).